<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>HTML实体</title>
</head>
<body>
<!--
    希望在页面中展现的内容为:<h1>Hello World</h1>
    由于<>属于关键字,会被处理掉
-->
<h1>&lt;h1&gt;Hello&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;World&lt;/h1&gt;</h1>
jdbc:mysql://127.0.0.1:3306/ums?useUnicode=true&amp;characterEncoding
</body>
</html>